A cloud streaming service basically applies a cloud streaming technique based on a video codec. Therefore, in case of a menu display or the like, the cloud streaming service is inefficient because of unnecessarily capturing the entire screen and encoding with the video codec.
Namely, as to a screen in which static images are slightly changed in response to a user input, an image-based cloud streaming service may be more efficient than a cloud streaming service using the video codec.
In other words, when a cloud streaming service based on a still image is performed, it is more efficient to detect a region changed between frames and then transmit such a minimum region only.
However, in case of applying a still image codec, the amount of data may be considerably varied depending on the type of an image to be compressed. Also, the efficiency of a cloud streaming service may be significantly varied depending on the still image compression technique used for compression. Therefore, a new technique for quickly and exactly identifying an image type and then adaptively applying an image cloud is required.
Additionally, for performing a cloud streaming service based on a still image, it is very important to exactly detect a region at which a change between frames occurs. Therefore, a technique for detecting such a changed region more simply and more effectively is also required.
Further, as cable or IPTV providers have been supplying various kinds of set-top boxes for a long time, there are wide differences in performance between such set-top boxes. In fact, more than 15 types of set-top boxes have been introduced in recent 10 years. The difference in performance between a good set-top box and a bad set-top box is so large that a content provider may not be able to provide contents to a user in a desired manner.
Besides, in case of a cloud streaming service based on a still image, web application developers who write a code for a web application want to write the code in the same way they used to be, whereas a cloud streaming server wants a code, to which no animation is applied, containing only information about an image requiring to be captured and information corresponding to the properties of animation. Namely, in order to provide a code desired by a CS server, web application developers need to write the code in a new way, rather than the way they used to be.
Relevant techniques are disclosed in Korean Patent Publication Nos. 10-2014-0076668 (Title: Method for providing game based on cloud streaming, system, client terminal and service apparatus), published on Jun. 23, 2013, and 10-2014-0027040 (Title: Adaptive predictive image compression system and method thereof), published on Mar. 6, 2014.